Drain



Nov. 3, 1 953 F. D. MOYER 2,657,821

' DRAIN Filed Nov. 2, 1949 2 Sheets-Sheet l Nov. 3, 1953 Y F. D. MOYER 2,657,821

' DRAIN Filed Nov. 2, 1949 2 Sh'ets-Sheet 2 Patented Nov. 3, 1953 DRAIN Frederick nMOy'er, Chicago, Ill., assignor to Chicago'Bridge & Iron Company, a corporation of Illinois Application November 2, 1949, Serial No. 125,063

2 Claims.

This invention relates to floating roof tanks and more particularly to a new and improved drain for a floating roof tank.

Floating roof tanks are quite generally employed for the storage of volatile liquids, particularly petroleum products, where it is desired to minimize evaporation losses. In this form of tank the top closure floats upon the surface of the stored product and rises and falls with the level of liquid within the tank. As the normal position of the floating roof is below the top edges of the tank it is clear that means must be provided for draining rain water from the surface of the roof in order to preserve its stability and buoyancy. Accordingly, it is customary to pitch the roof toward one or more sumps in which rain water is collected and to provide a conduit connected to the sump and leading downward therefrom through the liquid in the tank. In some cases the drain may be connected to an outlet outside of the tank and in other cases the rain water may be emptied directly upon the bottom of the tank. As the storage product is generally; lighter than water theaccumulation of rain water on the bottom does not interfere with operation of the tank and excessive accumulations maybe drained from the bottom at periodic intervals.

The most commonly employed drain is a flexible hose having one end attached to the sump and having its other end attached to an outlet at the bottom of the tank. Many difficulties, however, arise in the operation of a simple flexible drain. For eiiai'nple, should the drain become partially filled with air or vapor it is apt to loop upwardly in the stored product and thus destroy the normal gradient from the sump to the outlet. In addition as the roof becomes lower in the tank due to the lowering of the liquid level, the gradient of the hose through the liquid becomes increasingly smaller. In addition flexible hoses often become fouled if they are allowed to float freely in the tank. Further, drains of this nature are often ruptured when used in areas having below freezing weather when water on the tank bottom freezes around the hose and prevents its moving with the roof.

I have invented and am herein disclosing and claiming an improved drain for a floating roof tank. The drain of this invention comprises a flexible conduit provided with a series of spaced weights along its upper portion and whose lower portion is surrounded by a guard member pivoted at or near the bottom of the tank adjacent to the outlet. The weight of the guard member serves to depress the bottom portion of the hose with downward movement of the roof within the tank. In addition the guard member during its downward pivotal movement swings the upper portion of the hose over a platform on the bottom of the tank into which such upper portion may coil with further downward movement of the roof. The platform is so positioned as to maintain the hose above the level of water in the tank bottom and hence above any ice formations on the bottom. In order to avoid any strain on the flexible hose due to the Weight of the guard member I provide a flexible support attached to the roof and to the free end of the guard member and having a length shorter than the upper portion of the hose. Thus theweight of the guard memberis borne by the flexible support rather than by the hose.

In addition,the drain of this invention is easily replaceable without removing the tank from service.

A specific embodiment of the invention will be described in conjunction with the attached drawings in which: I

Fig. '1 is a side elevation of a floating roof tank embodying the invention, with the walls of the tank broken away for clarity of illustration, and showing the roof in two positions;

Fig. 2 is a top plan view of the apparatus shown in Fig. 1;

Fig. 3 is a fragmentary sectional view through the drain hose and V-shaped channel iron hose guard taken substantially along the line 3-3 in Fig. 1.

Referring now to the drawing, I show a floating roof tank 10 having cylindrical side walls II and a floating roof 12 the surfaceof the stored product. The roof is provided with a sump f3 therein into which water falling upon the surface of the roof may drain. Connected to the sump by means of a fitting I4 is a flexible drain hose l5 which leads downward therefrom to an outlet l6 spaced just above the bottom of the tank. In the specific embodiment shown the outlet leads outwardly through the side walls II and is controlled by a drain valve IT.

A hose guard in the form of a v-shaped channel iron 18 is pivotally mounted upon a pair of brackets I9 mounted on the bottom of the tank. The channel I 8 surrounds the lower portion of the hose and is adapted to guide the hose downwardly and toward a platform 2% located above the normal level of water accumulation on the bottom of the tank.

therein adapted to float upon As can be seen from the dotted portion of Fig. 1 which illustrates in the position of the apparatus as the roof approaches the bottom of the tank, the hose guard l8 swings the upper portion of the hose (that is the portion of the hose beyond the free end 2| of the hose guard l8) over the platform 20 so that the hose may coil thereon with further downward movement of the roof.

In order to assure the maintenance of the proper gradient in the upper portion of the hose I provide such portion with a plurality of weights 22 consisting, in the specific embodiment shown, of ribbons of lead wrapped around the flexible hose at spaced intervals.

A flexible support in the form of a chain 23 is secured to the roof and to the free end 2| of the hose guard 18. The length of the chain 23 is less than the length of the upper portion of the hose between the fitting l4 and the free end 2| of the hose guard in order that all strains of pivoting the hose guard be borne by the support rather than by the hose itself.

It will be noted that the lower portion of the hose remains substantially horizontal except when the roof is near the top of the tank to maintain a fairly steep gradient in the upper hose portion. When the roof is near the top of the tank, the hose bends at 24 where it leaves the lower end of the hose guard and enters the outlet. This desirable positioning of the hose is accomplished without the use of a pivotal connection as would be necessary were the lower portion of the hose and the outlet constructed of rigid pipes.

The drain may be replaced when necessary without removing the tank from service. To accomplish this, the upper end of the old hose is unbolted from the fitting l4 and drawn up through a manhole in the deck. The bottom end of the new hose is then secured to the upper end of the old hose. By removing the outside drain from the sidewalls, the old hose may be withdrawn through the side of the tank, drawing the new hose after it. When the old hose is entirely withdrawn, the new hose may then be detached therefrom and secured to the proper fittings.

While I have shown and described my invention in its preferred embodiments it is to be understood that it is capable of many modifications. The foregoing detailed description has been given for the purpose of explaining the invention and should not be taken as a limitation of my invention as defined in the appended claims.

I claim:

1. A drain for a sump in a floating roof tank comprising a flexible hose having its upper end connected to the sump and having its lower end connected to an outlet at the bottom of the tank,

said hose having external connections at the sump and said outlet permitting withdrawal of the hose and replacement thereof at any position of the roof in the tank, an inflexible elongated hose guard covering only the lower portion of the hose and having one end mounted on the bottom of the tank near the lower end of the hose for pivotal movement in a substantially vertical plane, a hose platform on the tank bottom and positioned under the other end of the hose guard when the guard is in a substantially horizontal position, said hose guard being shaped to permit withdrawal of the hose therefrom and being in the form of a channel iron positioned wtih its legs extending downwardly from its base and a flexible support attached to the roof and to said other end of the hose guard, said support having a length shorter than the remaining portion of the hose, to raise the hose guard and lower hose portion when the roof rises near the top of the tank.

2. A drain for a sump in a floating roof tank comprising a flexible hose having its upper end connected to the sump and having its lower end connected to an outlet at the bottom of the tank, said hose having external connections at the sump and said outlet permitting withdrawal of the hose and replacement thereof at any position of the roof in the tank, an inflexible elongated hose guard covering only the lower portion of the hose and having one end mounted on the bottom of the tank near the lower end of the hose for pivotal movement in a substantially vertical plane, a hose platform on the tank bottom and positioned under the other end of the hose guard when the guard is in a substantially horizontal position, said hose guard being in the form of an inverted trough having a portion over the hose with portions extending downwardly on either side of the hose and a flexible support attached to the roof and to said other end of the hose guard, said support having a length shorter than the remaining portion of the hose to raise the hose guard and lower hose portion when the roof rises near the top of the tank.

FREDERICK D. MOYER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,636,540 Wiggins July 19, 1927 1,668,792 Wiggins May 8, 1928 1,761,700 Bailey June 3, 1930 2,315,023 Stevenson Mar. 30, 1943 2,390,141 Wiggins Dec. 4, 1945 2,482,468 Cranmer Sept. 20, 1949 

